content: /*
   * Copyright 2012-2017 the original author or authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.ajoberstar.gradle.util;
  
  import java.util.concurrent.Callable;
  
  import groovy.lang.Closure;
  
  /**
   * Utility class for general {@code Object} related operations.
   * @since 0.1.0
   */
  public final class ObjectUtil {
      /**
       * Cannot instantiate
       * @throws AssertionError always
       */
      private ObjectUtil() {
          throw new AssertionError("Cannot instantiate this class");
      }
  
      /**
       * Unpacks the given object by recursively
       * calling the {@code call()} method if the
       * object is a {@code Closure} or {@code Callable}.
       * @param obj the object to unpack
       * @return the unpacked value of the object
       */
      @SuppressWarnings("rawtypes")
      public static Object unpack(Object obj) {
          Object value = obj;
          while (value != null) {
              if (value instanceof Closure) {
                  value = ((Closure) value).call();
              } else if (value instanceof Callable) {
                  try {
                      value = ((Callable) value).call();
                  } catch (Exception e) {
                      throw new RuntimeException(e);
                  }
              } else {
                  return value;
              }
          }
          return value;
      }
  
      /**
       * Unpacks the given object to its {@code String}
       * value.  Same behavior as the other {@code unpack}
       * method ending with a call to {@code toString()}.
       * @param obj the value to unpack
       * @return the unpacked string value
       * @see ObjectUtil#unpack(Object)
       */
      public static String unpackString(Object obj) {
          Object value = unpack(obj);
          return value == null ? null : value.toString();
      }
  }
  